AIM:To apply factorial design to investigate the main influence factors of corneal stroma bed thickness after laser in situ keratomileusis(LASIK) and their relevance.METHODS:Sixty eyes of 30 cases were randomly selected from patients treated with LASIK.Factorial design experiments were done with the main study factors such as preoperative intraocular pressure,degrees of refraction and thickness of postoperative corneal stroma bed.RESULTS:The difference between preoperative dioptres and the difference between preoperative dioptres and preoperative intraocular pressure were no statistically significant(P>0.05),there were statistical differences in the others.There were interaction among preoperative intraocular pressure,preoperative dioptre and thickness of postoperative corneal stroma bed(P<0.05 or P<0.01).CONCLUSION:The three factors can influence the surgical results.It will be more safe if preoperative intraocular pressure was under 21mmHg,preoperative dioptre was moderate and thickness of postoperative corneal stroma bed was above 300μm.